extensionFunction object

{
  "id": "{string}",
  "name": "{string}",
  "description": "{string}",
  "helpUrl": "{string}",
  "parameters": [
    {
      "name": "{string}",
      "description": "{string}",
      "type": "{string}",
      "cellValueType": "cellvalue | booleancellvalue | doublecellvalue | entitycellvalue | errorcellvalue | formattednumbercellvalue | linkedentitycellvalue | localimagecellvalue | stringcellvalue | webimagecellvalue | ",
      "dimensionality": "scalar | matrix",
      "optional": {boolean},
      "repeating": {boolean}
    }
  ],
  "result": {
    "dimensionality": "scalar | matrix"
  },
  "stream": {boolean},
  "volatile": {boolean},
  "cancelable": {boolean},
  "requiresAddress": {boolean},
  "requiresParameterAddress": {boolean}
}

{
  "type": "object",
  "properties": {
    "id": {
      "type": "string",
      "pattern": "^[a-zA-Z][a-zA-Z0-9._]*$",
      "description": "A unique ID for the function.",
      "minLength": 3,
      "maxLength": 64
    },
    "name": {
      "type": "string",
      "pattern": "^[\\p{L}][\\p{L}0-9._]*$",
      "description": "The name of the function that end users see in Excel. In Excel, this function name is prefixed by the custom functions namespace that\u0027s specified in the manifest file.",
      "minLength": 3,
      "maxLength": 64
    },
    "description": {
      "type": "string",
      "description": "The description of the function that end users see in Excel.",
      "minLength": 1,
      "maxLength": 128
    },
    "helpUrl": {
      "type": "string",
      "format": "uri",
      "description": "URL that provides information about the function. (It is displayed in a task pane.)",
      "minLength": 1,
      "maxLength": 2048
    },
    "parameters": {
      "type": "array",
      "description": "Array that defines the input parameters for the function.",
      "items": {
        "$ref": "#/definitions/extensionFunctionParameter"
      },
      "minItems": 0,
      "maxItems": 128
    },
    "result": {
      "$ref": "#/definitions/extensionResult"
    },
    "stream": {
      "type": "boolean",
      "description": "If true, the function can output repeatedly to the cell even when invoked only once. This option is useful for rapidly-changing data sources, such as a stock price. The function should have no return statement. Instead, the result value is passed as the argument of the StreamingInvocation.setResult callback function.",
      "default": false
    },
    "volatile": {
      "type": "boolean",
      "description": "If true, the function recalculates each time Excel recalculates, instead of only when the formula\u0027s dependent values have changed. A function can\u0027t use both the stream and volatile properties. If the stream and volatile properties are both set to true, the volatile property will be ignored.",
      "default": false
    },
    "cancelable": {
      "type": "boolean",
      "description": "If true, Excel calls the CancelableInvocation handler whenever the user takes an action that has the effect of canceling the function; for example, manually triggering recalculation or editing a cell that is referenced by the function. Cancelable functions are typically only used for asynchronous functions that return a single result and need to handle the cancellation of a request for data. A function can\u0027t use both the stream and cancelable properties.",
      "default": false
    },
    "requiresAddress": {
      "type": "boolean",
      "description": "If true, your custom function can access the address of the cell that invoked it. The address property of the invocation parameter contains the address of the cell that invoked your custom function. A function can\u0027t use both the stream and requiresAddress properties.",
      "default": false
    },
    "requiresParameterAddress": {
      "type": "boolean",
      "description": "If true, your custom function can access the addresses of the function\u0027s input parameters. This property must be used in combination with the dimensionality property of the result object, and dimensionality must be set to matrix.",
      "default": false
    }
  },
  "required": [
    "id",
    "name",
    "parameters",
    "result"
  ]
}